CXCR4 and plasma cell myeloma: CXCR4 can also be labelled with the cytotoxic beta-emitters such 177Lu or 90Y generating the novel theranostic agent Pentixather for CXCR4-directed endoradiotherapy [50•], which has already been used, with varying degrees of success, in multiple myeloma and other haemato-oncological diseases [51].